Historically, a subscriber television system operator provides a subscriber with a set-top terminal that allows the subscriber to receive and decrypt television programs and services. The set-top provides access to the subscriber television system, including providing conditional access for the specific subscriber television system. The subscriber television system uses conditional access to prevent unauthorized users from pirating or accessing the system services. A system subscriber “rented” the set-top from the subscriber television system by paying a monthly fee. Subscribers returned the set-top when they moved or changed service providers.
The Telecommunications Act of 1996, which is being implemented by the Federal Communications Commission (FCC), allows subscribers to buy a host terminal, also known as a consumer set-top terminal, from a variety of sources for use in any subscriber television system. The host terminal may be integrated into a videocassette recorder (VCR), television (TV), computer, or other similar device.
The operator of each subscriber television system has the responsibility of providing an interface for this subscriber owned equipment that allows it to function with the individual subscriber television system. To address the concern of the subscriber television system operators about conditional access and piracy, the FCC directed the Society of Cable Television Engineers (SCTE) to establish standards for what is referred to as an external conditional access module or a Point-of-Deployment (POD) module. The POD module provides a removable conditional access element for a host terminal. A POD module is provided by the individual subscriber television system and upon insertion into a host terminal, and upon receiving proper authorization, allows the decryption of encrypted conditional access services to prevent piracy. A POD module conforms generally to the Personal Computer Memory Card International Association (PCMCIA) standards. The POD module is typically a little larger than a credit card, is inserted into a slot in a host terminal, and communicates with the host terminal via a PCMCIA connector. The POD module would be removed from the host terminal and returned to the subscriber television system when the subscriber moves or changes service providers. The subscriber would get a new POD module from the next subscriber television system to which they elect to subscribe for services.
The subscriber television systems provide a large quantity of programs and services. The programs and services are typically provided to the subscriber via transport streams within a transmission signal. There can be multiple programs or services within a single transport stream and multiple transports streams within the transmission signal. A host terminal that wants to simultaneously display programming from two separate transport streams would use two tuners, one for each transport stream. This creates a problem in that there is the possibility that two transport streams need to be decrypted for conditional access. The SCTE specification limits the number of data streams that can be input at one time into a POD module to one. On a host terminal with Picture-in-Picture (PIP) functionality that requires two inputs, the host terminal would not be able to simultaneously decrypt the two data streams to provide both the main and the secondary picture data. A host terminal with multiple data streams, such as those with two or more tuners, must limit the decryption to one data stream from one tuner. The system subscriber that owns a host terminal with multiple tuners will want to use the functionality that is provided with those elements, such as PIP or the simultaneous taping and viewing of different programs. The operator of a subscriber television system needs to be able to provide a POD module that is capable of receiving multiple data streams for decryption to support the multiple tuner functionality. Thus, what is needed is a method, host terminal, and external conditional access module that allows the decryption of multiple data streams to support a multiple data stream host terminal.